The present invention relates to apparatus for the hydroponic culture of plants having a plant receiving insertion vessel preferably made of plastic material with a perforated wall and at least one ancillary device which is connectable to the vessel. Hydroponic insertion vessels are used for cultivating plants for hydroculture and are inserted individually or in groups together with the plants into hydroculture vessels.
It is already known in a plant receiving vessel of plastic material to provide a hole in the base of the vessel for inserting a water level indicator (see German Gebrauchsmuster No. 7339503). The water level indicator is inserted before planting whereupon the substratum and the plant to be cultivated are then charged. This operation is complicated by the presence of the water level indicator in the vessel space since such is not reliably anchored. As it cannot be foreseen as to which of the cultivated plants are finally charged individually or in groups in the hydroculture vessel, all vessels each have to be provided with a water level indicator since it is virtually impossible to subsequently insert a water level indicator into the vessel once filled with substratum and cultivated. When inserting the pre-cultivated plants in groups in hydroponic vessels therefor, all but one of the water level indicators should be removed from the inserted vessels which is a cumbersome or impossible task and generally harmful to the plants. Alternatively the water level indicators may be left inserted in all vessels but this, however, is uneconomical and undesirable from an aesthetic point of view.